The study, in Joule, was written by researchers at Carbon Engineering in Calgary, Canada, which has been operating a pilot CO2-extraction plant in British Columbia since 2015. That plant — based on a concept called direct air capture — provided the basis for the economic analysis, which includes cost estimates from commercial vendors of all of the major components. Depending on a variety of design options and economic assumptions, the cost of pulling a tonne of CO2 from the atmosphere ranges between US $94 and $232. The last comprehensive analysis of the technology, conducted by the American Physical Society in 2011, estimated that it would cost $600 per tonne.

Carbon Engineering says that it published the paper to advance discussions about the cost and potential of the technology. “We’re really trying to commercialize direct air capture in a serious way, and to do that, you have to have everybody in the supply chain on board,” says David Keith, acting chief scientist at Carbon Engineering and a climate physicist at Harvard University in Cambridge, Massachusetts.

Scientists in Japan now have permission to treat people who have heart disease with cells produced by a revolutionary reprogramming technique. The study is only the second clinical application of induced pluripotent stem (iPS) cells. These are created by inducing the cells of body tissues such as skin and blood to revert to an embryonic-like state, from which they can develop into other cell types.

On 16 May, Japan’s health ministry gave doctors the green light to take wafer-thin sheets of tissue derived from iPS cells and graft them onto diseased human hearts. The team, led by cardiac surgeon Yoshiki Sawa at Osaka University, says that the tissue sheets can help to regenerate the organ’s muscle when it becomes damaged, a symptom of heart disease that can be caused by a build-up of plaque or by a heart attack.

“It will excite worldwide attention, as many groups are working in the same direction,” says Thomas Eschenhagen, a pharmacologist at the University of Hamburg in Germany and chair of the German Centre for Cardiovascular Research.

China has taken its first major step in a groundbreaking lunar mission. On 21 May, a probe launched from Xichang Satellite Launch Centre to head beyond the Moon, where it will lie ready to act as a communications station for the Chang’e-4 lunar lander. The nation hopes that the lander will, later this year, become the first craft to touch down on the far side of the Moon.

The relay probe, named Queqiao and designed by the Chinese Academy of Sciences, also carries two pioneering radio-astronomy experiments. Both are proof-of-principle missions designed to test technologies for exploring a period in cosmic history known as the dark ages. These first few hundred million years of the Universe’s existence, before galaxies and stars began to form, are all but impossible to study from Earth. But the spectrum of radiation from this age — when matter was distributed nearly uniformly across space as a thin, cold haze — could reveal information about the distribution of ordinary matter compared with dark matter in the Universe.

The first experiment is the Netherlands-China Low-Frequency Explorer (NCLE). It will remain attached to Queqiao, which will linger around ‘Earth-Moon L2’ — a gravitational resting point about 60,000 kilometres beyond the Moon that tracks the Moon’s orbit around Earth (see ‘Far-side satellite’). The Dutch-built NCLE experiment will try to exploit the relative quiet there to measure radio waves with frequencies between about 1 megahertz and 80 megahertz, coming from the Solar System, the Galaxy and beyond. Much of this frequency band is blocked by Earth’s atmosphere, but cosmologists expect it to contain information from the dark ages. Around the upper end of this band also fall the ‘cosmic- dawn’ signals from the first stars, which lit up around 200 million years after the Big Bang and were apparently detected for the first time earlier this year. Other experiments are trying to replicate those results — but the NCLE is testing technologies for identifying lower-frequency signatures from the dark ages.)

Even some of the most powerful tech companies start out tiny, with a young innovator daydreaming about creating the next big thing. As today’s tech firms receive increased moral scrutiny, it raises a question about tomorrow’s: Is that young person thinking about the tremendous ethical responsibility they’d be taking on if their dream comes true?

Greg Epstein, the recently appointed humanist chaplain at MIT, sees his new role as key to helping such entrepreneurial students think through the ethical ramifications of their work. As many college students continue to move away from organized religion, some universities have appointed secular chaplains like Epstein to help non-religious students lead ethical, meaningful lives. At MIT, Epstein plans to spark conversations about the ethics of technology—conversations that will sometimes involve religious groups on campus, and that may sometimes carry over to Harvard, where he has held (and will continue to hold) the same position since 2005.

I recently spoke with Epstein about how young people can think ethically about going into the tech industry and what his role will look like. This interview has been lightly edited and condensed.

Amazon, Uber and other tech giants want to fill the skies with small autonomous aircraft ferrying packages and people from place to place. For that to happen, these robotic drones—also called unmanned aircraft systems (UASs)—need an air traffic control system to keep them from crashing into buildings, human-piloted aircraft or one another. NASA is developing a UAS Traffic Management (UTM) network with several other organizations that the group plans to finish testing next year. Uber, in particular, has a lot riding on the UTM’s success—the ride-sharing company made several announcements last week to promote its proposeduberAIR taxi service. Big questions remain, however, as to whether and when any monitoring and management system will be able to handle the expected volume of large self-flying aircraft, which will be traveling great distances to deliver everything from pizzas to passengers.

Uber is onboard with NASA, at least. The company announced at its Elevate aviation conference in Los Angeles on May 8 and 9 it had signed an agreement to provide NASA with details and data about the inaugural uberAIR service it has planned for Dallas–Fort Worth. In return, the agency will use Uber’s data to make computer simulations of small passenger-carrying aircraft flying over the Texas Metroplex during peak air traffic times. Uber will analyze those simulations to help plan air taxi management in the already crowded skies over Dallas as well as Los Angeles and Dubai—the other cities hoping to start testing uberAIR by 2020.

Uber is targeting urban areas that have a population of more than two million people and a density of more than “2,000 people per square mile,” according to documents on Uber’s Web site. The cities must also have a large and dispersed layout that allows air taxis “to offer significant time-saving benefits at speeds of” 240 to 320 kilometers per hour. The company also points out flights will go from “node to node rather than point to point,” meaning there will be specific—rather than random—pickup and drop-off sites.

Scientists have used artificial intelligence (AI) to recreate the complex neural codes that the brain uses to navigate through space. The feat demonstrates how powerful AI algorithms can assist conventional neuroscience research to test theories about the brain’s workings — but the approach is not going to put neuroscientists out of work just yet, say the researchers.

The computer program, details of which were published in Nature on 9 May1, was developed by neuroscientists at University College London (UCL) and AI researchers at the London-based Google company DeepMind. It used a technique called deep learning — a type of AI inspired by the structures in the brain — to train a computer-simulated rat to track its position in a virtual environment.

The program surprised the scientists by spontaneously generating hexagonal-shaped patterns of activity akin to those generated by navigational cells in the mammalian brain called grid cells. Grid cells have been shown in experiments with real rats to be fundamental to how an animal tracks its own position in space.

Researchers in China have developed a filter that removes salt from water up to three times as fast as conventional filters. The membrane has a unique nanostructure of tubular strands, inspired by the mathematical-biology work of codebreaker Alan Turing.

The filter is the most finely constructed example of the mathematician’s ‘Turing structures’ yet, and their first practical application, say researchers. “These 3D structures are quite extraordinary,” says Patrick Müller, a systems biologist at the Friedrich Miescher Laboratory in Tübingen, Germany. The filter’s tubular strands, just tens of nanometres in diameter, would be impossible to produce by other methods, such as 3D printing, he says. The work is published on 3 May in Science1.

British mathematician Alan Turing is best known for his codebreaking exploits for the UK government during the Second World War, and as the father of computer science and artificial intelligence. But he also produced a seminal work2 in the then-nascent field of mathematical biology in 1952, just two years before his death.

YouTube is a supercomputer working to achieve a specific goal — to get you to spend as much time on YouTube as possible.

But no one told its system exactly how to do that. After YouTube built the system that recommends videos to its users, former employees like Guillaume Chaslot, a software engineer in artificial intelligence who worked on the site’s recommendation engine in 2010-2011, said he watched as it started pushing users toward conspiracy videos. Chaslot said the platform’s complex “machine learning” system, which uses trial and error combined with statistical analysis to figure out how to get people to watch more videos, figured out that the best way to get people to spend more time on YouTube was to show them videos light on facts but rife with wild speculation.

Routine searches on YouTube can generate quality, personalized recommendations that lead to good information, exciting storytelling from independent voices, and authoritative news sources.

But they can also return recommendations for videos that assert, for example, that the Earth is flat, aliens are underneath Antarctica, and mass shooting survivors are crisis actors.

The stretchy material is made up of strands of copolymers — complex, self-assembling large molecules that in this case are shaped like long dumbbells, with spherical bulges on each end. The way those copolymers react to mechanical stress allows them to vary their stiffness and color, the researchers wrote in a paper published Friday (March 30) in the journal Science.

Like a chameleon, the substance doesn’t undergo any chemical changes when it changes color. Instead, those tiny bulges at the ends of the copolymers move closer together or farther apart, changing how they interact with light.

When the long copolymers weave together in cross-linked structures, the researchers wrote, they can “display vibrant color, extreme softness, and intense strain stiffening on par with that of skin tissue.

Thanks to NASA’s pioneering Kepler probe, we know our galaxy is teeming with exoplanets. Now, a new generation of exoplanet hunters is set to home in on rocky worlds closer to home.

Over 9 years in space, Kepler has found more than 2600 confirmed exoplanets, implying hundreds of billions in the Milky Way. The new efforts sacrifice sheer numbers and target Earth-size planets whose composition, atmosphere, and climate—factors in whether they might be hospitable to life—could be studied. Leading the charge is the Transiting Exoplanet Survey Satellite (TESS), a NASA mission due for launch on 16 April.

The brainchild of researchers at the Massachusetts Institute of Technology (MIT) in Cambridge, the $337 million TESS project aims to identify at least 50 rocky exoplanets—Earth-size or bigger—close enough for their atmospheres to be scrutinized by the much larger James Webb Space Telescope (JWST), due for launch in 2020. “Where do we point Webb?” TESS Principal Investigator George Ricker asked rhetorically at the American Astronomical Society annual meeting at National Harbor in Maryland in January. “This is the finder scope.”